Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Map often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Map, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
15 | final class Map implements \IteratorAggregate, \ArrayAccess, Collection |
||
16 | { |
||
17 | use Traits\GenericCollection; |
||
18 | use Traits\SquaredCapacity; |
||
19 | |||
20 | const MIN_CAPACITY = 8; |
||
21 | |||
22 | /** |
||
23 | * @var array internal array to store pairs |
||
24 | */ |
||
25 | private $pairs = []; |
||
26 | |||
27 | /** |
||
28 | * Creates a new instance. |
||
29 | * |
||
30 | * @param array|\Traversable|null $values |
||
31 | */ |
||
32 | 1024 | public function __construct($values = null) |
|
33 | { |
||
34 | 1024 | if (func_num_args()) { |
|
35 | 531 | $this->putAll($values); |
|
36 | } |
||
37 | 1024 | } |
|
38 | |||
39 | /** |
||
40 | * Updates all values by applying a callback function to each value. |
||
41 | * |
||
42 | * @param callable $callback Accepts two arguments: key and value, should |
||
43 | * return what the updated value will be. |
||
44 | */ |
||
45 | 5 | public function apply(callable $callback) |
|
46 | { |
||
47 | 5 | foreach ($this->pairs as &$pair) { |
|
48 | 4 | $pair->value = $callback($pair->key, $pair->value); |
|
49 | } |
||
50 | 2 | } |
|
51 | |||
52 | /** |
||
53 | * @inheritDoc |
||
54 | */ |
||
55 | 4 | public function clear() |
|
56 | { |
||
57 | 4 | $this->pairs = []; |
|
58 | 4 | $this->capacity = self::MIN_CAPACITY; |
|
59 | 4 | } |
|
60 | |||
61 | /** |
||
62 | * Return the first Pair from the Map |
||
63 | * |
||
64 | * @return Pair |
||
65 | * |
||
66 | * @throws UnderflowException |
||
67 | */ |
||
68 | 8 | public function first(): Pair |
|
69 | { |
||
70 | 8 | if ($this->isEmpty()) { |
|
71 | 2 | throw new UnderflowException(); |
|
72 | } |
||
73 | |||
74 | 6 | return $this->pairs[0]; |
|
75 | } |
||
76 | |||
77 | /** |
||
78 | * Return the last Pair from the Map |
||
79 | * |
||
80 | * @return Pair |
||
81 | * |
||
82 | * @throws UnderflowException |
||
83 | */ |
||
84 | 8 | public function last(): Pair |
|
85 | { |
||
86 | 8 | if ($this->isEmpty()) { |
|
87 | 2 | throw new UnderflowException(); |
|
88 | } |
||
89 | |||
90 | 6 | return $this->pairs[count($this->pairs) - 1]; |
|
91 | } |
||
92 | |||
93 | /** |
||
94 | * Return the pair at a specified position in the Map |
||
95 | * |
||
96 | * @param int $position |
||
97 | * |
||
98 | * @return Pair |
||
99 | * |
||
100 | * @throws OutOfRangeException |
||
101 | */ |
||
102 | 37 | public function skip(int $position): Pair |
|
103 | { |
||
104 | 37 | if ($position < 0 || $position >= count($this->pairs)) { |
|
105 | 13 | throw new OutOfRangeException(); |
|
106 | } |
||
107 | |||
108 | 24 | return $this->pairs[$position]->copy(); |
|
109 | } |
||
110 | |||
111 | /** |
||
112 | * Merge an array of values with the current Map |
||
113 | * |
||
114 | * @param array|\Traversable $values |
||
115 | * |
||
116 | * @return Map |
||
117 | */ |
||
118 | 44 | public function merge($values): Map |
|
119 | { |
||
120 | 44 | $merged = new self($this); |
|
121 | 44 | $merged->putAll($values); |
|
122 | 44 | return $merged; |
|
123 | } |
||
124 | |||
125 | /** |
||
126 | * Creates a new map containing the pairs of the current instance whose keys |
||
127 | * are also present in the given map. In other words, returns a copy of the |
||
128 | * current map with all keys removed that are not also in the other map. |
||
129 | * |
||
130 | * @param Map $map The other map. |
||
131 | * |
||
132 | * @return Map A new map containing the pairs of the current instance |
||
133 | * whose keys are also present in the given map. In other |
||
134 | * words, returns a copy of the current map with all keys |
||
135 | * removed that are not also in the other map. |
||
136 | */ |
||
137 | 24 | public function intersect(Map $map): Map |
|
138 | { |
||
139 | return $this->filter(function($key) use ($map) { |
||
140 | 20 | return $map->hasKey($key); |
|
141 | 24 | }); |
|
142 | } |
||
143 | |||
144 | /** |
||
145 | * Returns the result of removing all keys from the current instance that |
||
146 | * are present in a given map. |
||
147 | * |
||
148 | * @param Map $map The map containing the keys to exclude. |
||
149 | * |
||
150 | * @return Map The result of removing all keys from the current instance |
||
151 | * that are present in a given map. |
||
152 | */ |
||
153 | 24 | public function diff(Map $map): Map |
|
154 | { |
||
155 | return $this->filter(function($key) use ($map) { |
||
156 | 20 | return ! $map->hasKey($key); |
|
157 | 24 | }); |
|
158 | } |
||
159 | |||
160 | /** |
||
161 | * Determines whether two keys are equal. |
||
162 | * |
||
163 | * @param mixed $a |
||
164 | * @param mixed $b |
||
165 | * |
||
166 | * @return bool |
||
167 | */ |
||
168 | 625 | private function keysAreEqual($a, $b): bool |
|
169 | { |
||
170 | 625 | if (is_object($a) && $a instanceof Hashable) { |
|
171 | 18 | return get_class($a) === get_class($b) && $a->equals($b); |
|
172 | } |
||
173 | |||
174 | 621 | return $a === $b; |
|
175 | } |
||
176 | |||
177 | /** |
||
178 | * Attempts to look up a key in the table. |
||
179 | * |
||
180 | * @param $key |
||
181 | * |
||
182 | * @return Pair|null |
||
183 | */ |
||
184 | 706 | private function lookupKey($key) |
|
185 | { |
||
186 | 706 | foreach ($this->pairs as $pair) { |
|
187 | 618 | if ($this->keysAreEqual($pair->key, $key)) { |
|
188 | 618 | return $pair; |
|
189 | } |
||
190 | } |
||
191 | 706 | } |
|
192 | |||
193 | /** |
||
194 | * Attempts to look up a key in the table. |
||
195 | * |
||
196 | * @param $value |
||
197 | * |
||
198 | * @return Pair|null |
||
199 | */ |
||
200 | 5 | private function lookupValue($value) |
|
201 | { |
||
202 | 5 | foreach ($this->pairs as $pair) { |
|
203 | 4 | if ($pair->value === $value) { |
|
204 | 4 | return $pair; |
|
205 | } |
||
206 | } |
||
207 | 3 | } |
|
208 | |||
209 | /** |
||
210 | * Returns whether an association a given key exists. |
||
211 | * |
||
212 | * @param mixed $key |
||
213 | * |
||
214 | * @return bool |
||
215 | */ |
||
216 | 69 | public function hasKey($key): bool |
|
217 | { |
||
218 | 69 | return $this->lookupKey($key) !== null; |
|
219 | } |
||
220 | |||
221 | /** |
||
222 | * Returns whether an association for a given value exists. |
||
223 | * |
||
224 | * @param mixed $value |
||
225 | * |
||
226 | * @return bool |
||
227 | */ |
||
228 | 5 | public function hasValue($value): bool |
|
229 | { |
||
230 | 5 | return $this->lookupValue($value) !== null; |
|
231 | } |
||
232 | |||
233 | /** |
||
234 | * @inheritDoc |
||
235 | */ |
||
236 | 715 | public function count(): int |
|
237 | { |
||
238 | 715 | return count($this->pairs); |
|
239 | } |
||
240 | |||
241 | /** |
||
242 | * Returns a new map containing only the values for which a predicate |
||
243 | * returns true. A boolean test will be used if a predicate is not provided. |
||
244 | * |
||
245 | * @param callable|null $callback Accepts a key and a value, and returns: |
||
246 | * true : include the value, |
||
247 | * false: skip the value. |
||
248 | * |
||
249 | * @return Map |
||
250 | */ |
||
251 | 76 | public function filter(callable $callback = null): Map |
|
252 | { |
||
253 | 76 | $filtered = new self(); |
|
254 | |||
255 | 76 | foreach ($this as $key => $value) { |
|
256 | 63 | if ($callback ? $callback($key, $value) : $value) { |
|
257 | 62 | $filtered->put($key, $value); |
|
258 | } |
||
259 | } |
||
260 | |||
261 | 73 | return $filtered; |
|
262 | } |
||
263 | |||
264 | /** |
||
265 | * Returns the value associated with a key, or an optional default if the |
||
266 | * key is not associated with a value. |
||
267 | * |
||
268 | * @param mixed $key |
||
269 | * @param mixed $default |
||
270 | * |
||
271 | * @return mixed The associated value or fallback default if provided. |
||
272 | * |
||
273 | * @throws OutOfBoundsException if no default was provided and the key is |
||
274 | * not associated with a value. |
||
275 | */ |
||
276 | 33 | public function get($key, $default = null) |
|
277 | { |
||
278 | 33 | if (($pair = $this->lookupKey($key))) { |
|
279 | 29 | return $pair->value; |
|
280 | } |
||
281 | |||
282 | // Check if a default was provided. |
||
283 | 4 | if (func_num_args() === 1) { |
|
284 | 1 | throw new OutOfBoundsException(); |
|
285 | } |
||
286 | |||
287 | 3 | return $default; |
|
288 | } |
||
289 | |||
290 | /** |
||
291 | * Returns a set of all the keys in the map. |
||
292 | * |
||
293 | * @return Set |
||
294 | */ |
||
295 | 37 | public function keys(): Set |
|
296 | { |
||
297 | $key = function($pair) { |
||
298 | 19 | return $pair->key; |
|
299 | 37 | }; |
|
300 | |||
301 | 37 | return new Set(array_map($key, $this->pairs)); |
|
302 | } |
||
303 | |||
304 | /** |
||
305 | * Returns a new map using the results of applying a callback to each value. |
||
306 | * |
||
307 | * The keys will be equal in both maps. |
||
308 | * |
||
309 | * @param callable $callback Accepts two arguments: key and value, should |
||
310 | * return what the updated value will be. |
||
311 | * |
||
312 | * @return Map |
||
313 | */ |
||
314 | 5 | public function map(callable $callback): Map |
|
315 | { |
||
316 | $apply = function($pair) use ($callback) { |
||
317 | 4 | return $callback($pair->key, $pair->value); |
|
318 | 5 | }; |
|
319 | |||
320 | 5 | return new self(array_map($apply, $this->pairs)); |
|
321 | } |
||
322 | |||
323 | /** |
||
324 | * Returns a sequence of pairs representing all associations. |
||
325 | * |
||
326 | * @return Sequence |
||
327 | */ |
||
328 | 7 | public function pairs(): Sequence |
|
329 | { |
||
330 | $copy = function($pair) { |
||
331 | 5 | return $pair->copy(); |
|
332 | 7 | }; |
|
333 | |||
334 | 7 | return new Vector(array_map($copy, $this->pairs)); |
|
335 | } |
||
336 | |||
337 | /** |
||
338 | * Associates a key with a value, replacing a previous association if there |
||
339 | * was one. |
||
340 | * |
||
341 | * @param mixed $key |
||
342 | * @param mixed $value |
||
343 | */ |
||
344 | 698 | public function put($key, $value) |
|
345 | { |
||
346 | 698 | $pair = $this->lookupKey($key); |
|
347 | |||
348 | 698 | if ($pair) { |
|
349 | 64 | $pair->value = $value; |
|
350 | |||
351 | } else { |
||
352 | 698 | $this->adjustCapacity(); |
|
353 | 698 | $this->pairs[] = new Pair($key, $value); |
|
354 | } |
||
355 | 698 | } |
|
356 | |||
357 | /** |
||
358 | * Creates associations for all keys and corresponding values of either an |
||
359 | * array or iterable object. |
||
360 | * |
||
361 | * @param \Traversable|array $values |
||
362 | */ |
||
363 | 531 | public function putAll($values) |
|
364 | { |
||
365 | 531 | foreach ($values as $key => $value) { |
|
366 | 329 | $this->put($key, $value); |
|
367 | } |
||
368 | 531 | } |
|
369 | |||
370 | /** |
||
371 | * Iteratively reduces the map to a single value using a callback. |
||
372 | * |
||
373 | * @param callable $callback Accepts the carry, key, and value, and |
||
374 | * returns an updated carry value. |
||
375 | * |
||
376 | * @param mixed|null $initial Optional initial carry value. |
||
377 | * |
||
378 | * @return mixed The carry value of the final iteration, or the initial |
||
379 | * value if the map was empty. |
||
380 | */ |
||
381 | 8 | public function reduce(callable $callback, $initial = null) |
|
382 | { |
||
383 | 8 | $carry = $initial; |
|
384 | |||
385 | 8 | foreach ($this->pairs as $pair) { |
|
386 | 6 | $carry = $callback($carry, $pair->key, $pair->value); |
|
387 | } |
||
388 | |||
389 | 6 | return $carry; |
|
390 | } |
||
391 | |||
392 | /** |
||
393 | * Completely removes a pair from the internal array by position. It is |
||
394 | * important to remove it from the array and not just use 'unset'. |
||
395 | */ |
||
396 | 28 | private function delete(int $position) |
|
397 | { |
||
398 | 28 | $pair = $this->pairs[$position]; |
|
399 | 28 | $value = $pair->value; |
|
400 | |||
401 | 28 | array_splice($this->pairs, $position, 1, null); |
|
402 | 28 | $this->adjustCapacity(); |
|
403 | |||
404 | 28 | return $value; |
|
405 | } |
||
406 | |||
407 | /** |
||
408 | * Removes a key's association from the map and returns the associated value |
||
409 | * or a provided default if provided. |
||
410 | * |
||
411 | * @param mixed $key |
||
412 | * @param mixed $default |
||
413 | * |
||
414 | * @return mixed The associated value or fallback default if provided. |
||
415 | * |
||
416 | * @throws \OutOfBoundsException if no default was provided and the key is |
||
417 | * not associated with a value. |
||
418 | */ |
||
419 | 34 | public function remove($key, $default = null) |
|
420 | { |
||
421 | 34 | foreach ($this->pairs as $position => $pair) { |
|
422 | 30 | if ($this->keysAreEqual($pair->key, $key)) { |
|
423 | 30 | return $this->delete($position); |
|
424 | } |
||
425 | } |
||
426 | |||
427 | // Check if a default was provided |
||
428 | 9 | if (func_num_args() === 1) { |
|
429 | 1 | throw new \OutOfBoundsException(); |
|
430 | } |
||
431 | |||
432 | 8 | return $default; |
|
433 | } |
||
434 | |||
435 | /** |
||
436 | * Returns a reversed copy of the map. |
||
437 | * |
||
438 | * @return Map |
||
|
|||
439 | */ |
||
440 | 15 | public function reverse() |
|
441 | { |
||
442 | 15 | $this->pairs = array_reverse($this->pairs); |
|
443 | 15 | } |
|
444 | |||
445 | /** |
||
446 | * Returns a reversed copy of the map. |
||
447 | * |
||
448 | * @return Map |
||
449 | */ |
||
450 | 5 | public function reversed(): Map |
|
451 | { |
||
452 | 5 | $reversed = new self(); |
|
453 | 5 | $reversed->pairs = array_reverse($this->pairs); |
|
454 | |||
455 | 5 | return $reversed; |
|
456 | } |
||
457 | |||
458 | /** |
||
459 | * Returns a sub-sequence of a given length starting at a specified offset. |
||
460 | * |
||
461 | * @param int $offset If the offset is non-negative, the map will |
||
462 | * start at that offset in the map. If offset is |
||
463 | * negative, the map will start that far from the |
||
464 | * end. |
||
465 | * |
||
466 | * @param int|null $length If a length is given and is positive, the |
||
467 | * resulting set will have up to that many pairs in |
||
468 | * it. If the requested length results in an |
||
469 | * overflow, only pairs up to the end of the map |
||
470 | * will be included. |
||
471 | * |
||
472 | * If a length is given and is negative, the map |
||
473 | * will stop that many pairs from the end. |
||
474 | * |
||
475 | * If a length is not provided, the resulting map |
||
476 | * will contains all pairs between the offset and |
||
477 | * the end of the map. |
||
478 | * |
||
479 | * @return Map |
||
480 | */ |
||
481 | 400 | public function slice(int $offset, int $length = null): Map |
|
482 | { |
||
483 | 400 | $map = new self(); |
|
484 | |||
485 | 400 | if (func_num_args() === 1) { |
|
486 | 100 | $slice = array_slice($this->pairs, $offset); |
|
487 | } else { |
||
488 | 300 | $slice = array_slice($this->pairs, $offset, $length); |
|
489 | } |
||
490 | |||
491 | 400 | foreach ($slice as $pair) { |
|
492 | 140 | $map->put($pair->key, $pair->value); |
|
493 | } |
||
494 | |||
495 | 400 | return $map; |
|
496 | } |
||
497 | |||
498 | /** |
||
499 | * Sorts the map in-place, based on an optional callable comparator. |
||
500 | * |
||
501 | * The map will be sorted by value. |
||
502 | * |
||
503 | * @param callable|null $comparator Accepts two values to be compared. |
||
504 | */ |
||
505 | 12 | View Code Duplication | public function sort(callable $comparator = null) |
506 | { |
||
507 | 12 | if ($comparator) { |
|
508 | usort($this->pairs, function($a, $b) use ($comparator) { |
||
509 | 4 | return $comparator($a->value, $b->value); |
|
510 | 6 | }); |
|
511 | |||
512 | } else { |
||
513 | usort($this->pairs, function($a, $b) { |
||
514 | 4 | return $a->value <=> $b->value; |
|
515 | 6 | }); |
|
516 | } |
||
517 | 12 | } |
|
518 | |||
519 | /** |
||
520 | * Returns a sorted copy of the map, based on an optional callable |
||
521 | * comparator. The map will be sorted by value. |
||
522 | * |
||
523 | * @param callable|null $comparator Accepts two values to be compared. |
||
524 | * |
||
525 | * @return Map |
||
526 | */ |
||
527 | 6 | public function sorted(callable $comparator = null): Map |
|
528 | { |
||
529 | 6 | $copy = $this->copy(); |
|
530 | 6 | $copy->sort($comparator); |
|
531 | 6 | return $copy; |
|
532 | } |
||
533 | |||
534 | /** |
||
535 | * Sorts the map in-place, based on an optional callable comparator. |
||
536 | * |
||
537 | * The map will be sorted by key. |
||
538 | * |
||
539 | * @param callable|null $comparator Accepts two keys to be compared. |
||
540 | */ |
||
541 | 16 | View Code Duplication | public function ksort(callable $comparator = null) |
554 | |||
555 | /** |
||
556 | * Returns a sorted copy of the map, based on an optional callable |
||
557 | * comparator. The map will be sorted by key. |
||
558 | * |
||
559 | * @param callable|null $comparator Accepts two keys to be compared. |
||
560 | * |
||
561 | * @return Map |
||
562 | */ |
||
563 | 6 | public function ksorted(callable $comparator = null): Map |
|
564 | { |
||
565 | 6 | $copy = $this->copy(); |
|
566 | 6 | $copy->ksort($comparator); |
|
567 | 6 | return $copy; |
|
568 | } |
||
569 | |||
570 | /** |
||
571 | * Returns the sum of all values in the map. |
||
572 | * |
||
573 | * @return int|float The sum of all the values in the map. |
||
574 | */ |
||
575 | 7 | public function sum() |
|
576 | { |
||
577 | 7 | return $this->values()->sum(); |
|
578 | } |
||
579 | |||
580 | /** |
||
581 | * @inheritDoc |
||
582 | */ |
||
583 | 414 | public function toArray(): array |
|
584 | { |
||
585 | 414 | $array = []; |
|
586 | |||
593 | |||
594 | /** |
||
595 | * Returns a sequence of all the associated values in the Map. |
||
596 | * |
||
597 | * @return Sequence |
||
598 | */ |
||
599 | 10 | public function values(): Sequence |
|
607 | |||
608 | /** |
||
609 | * Creates a new map that contains the pairs of the current instance as well |
||
610 | * as the pairs of another map. |
||
611 | * |
||
612 | * @param Map $map The other map, to combine with the current instance. |
||
613 | * |
||
614 | * @return Map A new map containing all the pairs of the current |
||
615 | * instance as well as another map. |
||
616 | */ |
||
617 | 12 | public function union(Map $map): Map |
|
621 | |||
622 | /** |
||
623 | * Creates a new map using keys of either the current instance or of another |
||
624 | * map, but not of both. |
||
625 | * |
||
626 | * @param Map $map |
||
627 | * |
||
628 | * @return Map A new map containing keys in the current instance as well |
||
629 | * as another map, but not in both. |
||
630 | */ |
||
631 | public function xor(Map $map): Map |
||
637 | |||
638 | /** |
||
639 | * @inheritDoc |
||
640 | */ |
||
641 | 535 | public function getIterator() |
|
647 | |||
648 | /** |
||
649 | * Returns a representation to be used for var_dump and print_r. |
||
650 | */ |
||
651 | 3 | public function __debugInfo() |
|
655 | |||
656 | /** |
||
657 | * @inheritdoc |
||
658 | */ |
||
659 | 5 | public function offsetSet($offset, $value) |
|
663 | |||
664 | /** |
||
665 | * @inheritdoc |
||
666 | * |
||
667 | * @throws OutOfBoundsException |
||
668 | */ |
||
669 | 18 | public function &offsetGet($offset) |
|
679 | |||
680 | /** |
||
681 | * @inheritdoc |
||
682 | */ |
||
683 | 4 | public function offsetUnset($offset) |
|
687 | |||
688 | /** |
||
689 | * @inheritdoc |
||
690 | */ |
||
691 | 20 | public function offsetExists($offset) |
|
695 | } |
||
696 |
This check compares the return type specified in the
@return
annotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.